Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of Finisar (Nasdaq: FNSR) fell nearly 14% in early trading and closed off 12.6%. The optical-networking specialist reported mixed fiscal second-quarter results and a disappointing Q3 outlook.

So what: Finisar earned $0.23 a share of Non-GAAP profit on $241.5 million in revenue in Q2. Analysts were expecting $0.22 and $242.2 million, respectively, according to data compiled by Yahoo! Finance.

Now what: Finisar wasn't the only loser among optical networkers. Investors sold shares of Oclaro (Nasdaq: OCLR) and NeoPhotonics (Nasdaq: NPTN), too -- both stocks were off more than 8%. Do you believe the drops were deserved? Or are you buying Finisar and its peers at current prices? Please weigh in using the comments box below.

Interested in more information about Finisar? Add it to your watchlist.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.